baldwin



i tiueness to that on the valve.

' i. w. BALDWIN, or,LAGONIAQNEWHAMPsHIRE.

Letters Patent N .99,812, dated February`15,1 870.

IMPROVEMENT IN GLOBE-VALVES.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern Be it known that I, J. W, BALDWIN,of Laconia,in the county of Belknap, and State of New Hampshire, have invented anew and useful Improvementin Globe- Valves, Vand other valvesof similaraction; and I do hereby declare that the following is a full and exactdescription thereof, reference being had to the accompan ying drawingsmaking part oi this specification.

liigure l is a cent-ral section of a globe-valve constructed with myimprovement. Figure 2, a centra-l section of a globe-valve, showing amodified arrangement of my improvement. p Figure 3, a correspondingsection of aglobe-valve, showing another modified arrangement of theimprovement. Y

' Figure 4, a plan and partial section of lthe valve, as arranged inrigs. 2 and 3, the view being at right .angles to that in those figures.i

Figure 5., a central longitudinal vertical section of a try-cockconstructed with theimprovement. Like letters designate corresponding.parts in all of the figures. l i i My improvement consists in providingtheperiphery of the valve with a screw-thread, and a correspondingscrew-thread in the` valve-seat, to receive that on the valve, the valve and `the valve-seat aperture being somewhat conical, in orderthatthe screv -threads may tighten togetheras the valve is screwed down, andthe valve being raised and` lowered by a screw ot' equal The ordinarymodes in which and apply my improvement, I have represented in theaccompanying drawings, and will here describe.

Letter A represents the valve, and B, the valve-seat. lhe screw-threadsin the peripheries thereof are represented at b, one fitting into theother as when the valve is closed. The degree of. couicality or y tapermay he about as indicated in the drawings., or

greater or less,ii` it should be preferable to vary there-- ii-om, nospecial angle being essential. .V

To open and close the valve it is to bescrewed out and-in by turnngthevalve-stem a in the ordinary way for smooth conical valves.

p In tig. l is shown a screwthread,`o, on thestem'ot' the valve forthepurpose.. 'In all cases the operating thread c should have the samedegree of tineness as the threads bin the valve and valve-seat, sothatthey will work' together in harmony. y

Iii-figs. 2, 3, and 4, `the operating screw-thread is upon the valveitself, being represented at d, continu# ous with thevalve-fitting'threadb, though upon'a cylindrical portion of the valve. il This screw-thread is represen ted as turning in screw- 1 propose toconstruct.`

' a key, g, lits, the .sha-ft a thereof extending outward through' astutling-box, and having a Harige, a, that turnsin a groove within thesame, or an equivalent device -by which the key is prevented from movingendwise while the valve itself travels up and down on the key,substantially as represented.

Notonly-are the operating screw and that on the valve of equal lineness,hut they are so arranged in relation to each other that the formerwillalways cause the latter lto take into the screw-thread in' thevalve-seat when the valve is closing. i Other modifications of the modeof applyingthe invention may suggest themselves, all embodying theprinciple of my invention'. i y

This improvement is applicable not only to globe' and similar valvesfor. stopp'` ig steam passages, but to other valves for air, gases, andliquids.

Fig. 5 indicates how the invention may he applied to try-cocksptheconioal screw-thread valve A closing the aperture between theeduction-passage manddischarge-passage n.

The` great advantage of thisinventiom isthat it closes the valveperfectly tight against any pressure ofthe steam or other duid, thescrew-threads tightening at theirgedges and furnishwing as manyvalve-seats as they have turns closing the joint. lt is 'also verydurable and little liable to get injured or outof shape, since the forceof the pressure is lateral into thebottom ot'thescrew-threads, and notdownward upon the valve-seat as with the ordinary smooth conical valve,.and however much-the valve ,may wear it constantly ts the s'eat, onlyentering a little further therein as i the wearing continues. y v I y'hWhat Il claim as my invention, and desire to secure by Letters Patent,is-

A conical valve A, `and valve-seat B, provided with screw-threads l)intheir 'peripheries fitting each other to4 tighten the valve, which is,operated by a screw of equal tineness with the said screw-threads,substantially as and 'for the purposes herein specified. i

i J.,W. BALDWIN.

Witnesses:

J. S. BROWN,

